# US 9,520,540 B2 · Light-emitting device with phosphor excited by blue excitation light

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- Number: US 9,520,540 B2
- Document ID: US9520540B2
- Status: Granted
- Kind: B2
- Application number: 14/184,881
- Filed: 2014-02-20
- Published: 2014-09-11
- Granted: 2016-12-13
- Earliest claimed: 2013-03-07
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Kunio Ishida; Keiko Albessard; Yasushi Hattori; Iwao Mitsuishi; Yumi Fukuda; Ryosuke Hiramatsu; Aoi Okada; Masahiro Kato
- Web page: https://patentgrep.com/patent/US9520540B2

## CPC

- H10H 20/8513: {having two or more wavelength conversion materials}
- C09K 11/77218: {Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides}
- C09K 11/77348: {Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides}
- H10H 20/8512: {Wavelength conversion materials}
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

A light-emitting device of an embodiment includes a light-emitting element emitting blue excitation light and a first phosphor excited by the blue excitation light and emitting fluorescence. A peak wavelength of the fluorescence is not shorter than 520 nm and shorter than 660 nm and the peak wavelength of the fluorescence shifting in the same direction when a peak wavelength of the blue excitation light shifts. The first phosphor is one of a yellow phosphor emitting yellow fluorescence, a green phosphor emitting green fluorescence, a yellow-green/yellow phosphor emitting yellow-green/yellow fluorescence and a red phosphor emitting red fluorescence.

## Claims

### Claim 1

A light-emitting device, comprising:
a light-emitting element emitting blue excitation light; and
a first phosphor excited by the blue excitation light and emitting fluorescence, a peak wavelength of the fluorescence being not shorter than 520 nm and shorter than 660 nm, an x coordinate of chromaticity of the fluorescence being increased and a y coordinate of chromaticity of the fluorescence being decreased when an x coordinate of chromaticity of the blue excitation light being decreased and a y coordinate of chromaticity of the blue excitation light being increased, the first phosphor being one of a yellow phosphor emitting yellow fluorescence, a green phosphor emitting green fluorescence, a yellow-green/yellow phosphor emitting yellow-green/yellow fluorescence and a red phosphor emitting red fluorescence.

### Claim 2 (depends on 1)

The device according to claim 1, wherein the first phosphor is the yellow-green/yellow phosphor.

### Claim 3 (depends on 1)

The device according to claim 1, wherein the first phosphor is the yellow-green/yellow phosphor represented by general equation (1), where x1, a1, b1, c1, and d1 satisfy relationships of 0<x1<1, 0.6<a1<0.95, 2.0<b1<3.9, 0<c1<0.45, and 4.0<d1<5.0, respectively
(Sr1-x1Cex1)a1AlSib1Oc1Nd1 (1).

### Claim 4 (depends on 3)

The device according to claim 3, further comprising a second phosphor being a green phosphor represented by general expression (2), where x2, a2, b2, c2, and d2 satisfy relationships of 0<x2<1, 0.93<a2<1.3, 4.0<b2<5.8, 0.6<c2<1.0, and 6.0<d2<11, respectively
(Sr1-x2Eux2)a2AlSib2Oc2Nd2 (2).

### Claim 5 (depends on 4)

The device according to claim 4, further comprising a third phosphor bring a red phosphor represented by general expression (3), where x3, a3, b3, c3, and d3 satisfy relationships of 0<x3<1, 0.6<a3<0.95, 2.0<b3<3.9, 0.25<c3<0.45, and 4.0<d3<5.0, respectively
(Sr1-x3Eux3)a3AlSib3Oc3Nd3 (3).

### Claim 6 (depends on 1)

The device according to claim 1, further comprising a light-adjusting mechanism changing emission intensity of the light-emitting element.

### Claim 7

A light-emitting device, comprising:
a light-emitting element emitting blue excitation light; and
a first phosphor excited by the blue excitation light and emitting fluorescence, a peak wavelength of the fluorescence being not shorter than 520 nm and shorter than 660 nm, an x coordinate of chromaticity of the fluorescence being increased and a y coordinate of chromaticity of the fluorescence being decreased when a peak wavelength of the blue excitation light shifts to a longer wavelength, the first phosphor being one of a yellow phosphor emitting yellow fluorescence, a green phosphor emitting green fluorescence, a yellow-green/yellow phosphor emitting yellow-green/yellow fluorescence and a red phosphor emitting red fluorescence.

### Claim 8 (depends on 7)

The device according to claim 7, wherein the first phosphor is the yellow-green/yellow phosphor.

### Claim 9 (depends on 7)

The device according to claim 7, wherein the peak wavelength of the fluorescence of the first phosphor shifts by 20 nm or more when the peak wavelength of the blue excitation light shifts from 420 nm to 460 nm.

### Claim 10 (depends on 7)

The device according to claim 7, wherein the first phosphor is a yellow-green/yellow phosphor represented by general equation (1), where x1, a1, b1, c1, and d1 satisfy relationships of 0<x1<1, 0.6<a1<0.95, 2.0<b1<3.9, 0<c1<0.45, and 4.0<d1<5.0, respectively
(Sr1-x1Cex1)a1AlSib1Oc1Nd1 (1).

### Claim 11 (depends on 10)

The device according to claim 10, further comprising a second phosphor being a green phosphor represented by general expression (2), where x2, a2, b2, c2, and d2 satisfy relationships of 0<x2<1, 0.93<a2<1.3, 4.0<b2<5.8, 0.6<c2<1.0, and 6.0<d2<11, respectively
(Sr1-x2Eux2)a2AlSib2Oc2Nd2 (2).

### Claim 12 (depends on 11)

The device according to claim 11, further comprising a third phosphor bring a red phosphor represented by general expression (3), where x3, a3, b3, c3, and d3 satisfy relationships of 0<x3<1, 0.6<a3<0.95, 2.0<b3<3.9, 0.25<c3<0.45, and 4.0<d3<5.0, respectively
(Sr1-x3Eux3)a3AlSib3Oc3Nd3 (3).

### Claim 13 (depends on 7)

The device according to claim 7, further comprising: a light-adjusting mechanism configured to change emission intensity of the light-emitting element.